1. FIELD OF THE INVENTION
The present invention relates to a drive system for a thin-film electroluminescent (EL) matrix display panel.
2. DESCRIPTION OF THE PRIOR ART
The conventional drive circuit for a thin-film electroluminescent (EL) matrix display panel includes high-voltage N-ch MOS drivers performing pull-down function, and diodes performing pull-up function. An example of the conventional drive circuit is disclosed in Nikkei Electronics, April 2, 1979, "Practical Applications of Thin-Film Electroluminescent (EL) Character Display".
In such a conventional drive circuit, the phase relationship between the write pulse and the field refresh pulse sequentially varies depending on the scanning electrodes. And, the pre-charging voltage produces a D.C. voltage depending on whether the data side electrode is selected or is not selected. Furthermore, the amplitudes of the write voltage and the refresh pulse are asymmetrical to each other. This creates deterioration in the voltage-brightness characteristics of the alternating current driving thin-film electroluminescent (EL) matrix display panel. Therefore, the conventional drive circuit can not ensure a stable operation of the thin-film electroluminescent (EL) matrix display panel for a long time.